Earlier this year, Charles opened up about his sister's tragic death as part of ABC documentary The Story of Diana.

"Nothing in her life came close to the love for her children," he said.

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"They meant more to her than anything.

"One of the reasons I wanted to talk now is because I think after 20 years, somebody shifts from being a contemporary person to one of history, actually.
"And Diana deserves a place in history. This was a special person, and not just a beautiful one."